/*
 * Copyright 2010, 2011 mapsforge.org
 *
 * This program is free software: you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with
 * this program. If not, see <http://www.gnu.org/licenses/>.
 */
package org.mapsforge.routing.preprocessing.hh.mobile;

import java.io.Serializable;
import java.util.Collection;

/**
 * A Clustering represents a set of clusters, which are disjoint sets of vertices.
 */
public interface Clustering extends Serializable {

	/**
	 * Lookup the cluster the given vertex belongs to.
	 * 
	 * @param vertexId
	 *            the vertex whose cluster is queried.
	 * @return the cluster the given vertex belongs to.
	 */
	public Cluster getCluster(int vertexId);

	/**
	 * @return all clusters within this clustering.
	 */
	public Collection<? extends Cluster> getClusters();

	/**
	 * @return the number of clusters.
	 */
	public int size();

}
